This application claims the priority of German application 198 50 685, filed in Germany on Nov. 3, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a selecting device for an automatic transmission of a motor vehicle. Preferred embodiments of the invention relate to a selecting device for selecting operating positions of an automatic transmission of a motor vehicle by deflecting a selector lever, which selector lever automatically moves back from all deflecting directions for selecting the individual operating positions and by means of which the automatic transmission can be controlled in a first operating mode--selection of individual driving positions in the automatic operation--or in a second operating mode--step-by-step shifting of the gears in the manual operation--by means of a transmission control device, for each operating mode, one operating position respectively of the automatic transmission being assigned to each deflection direction of the selector lever.
It is known to design an automatically shifted motor vehicle transmission and its selecting device such that, by means of the selecting device, the driver can choose between a step-by-step shifting operation and an automatic driving position operation.
In the case of the automatic driving position operation, the operating range of the automatically shifted motor vehicle transmission is divided into different, manually preselectable operating steps which are called driving positions and which represent the different vehicle operating conditions. The term "driving positions", as it is used here, comprises all operating steps of an automatically shifted motor vehicle transmission, thus also the parking position and the neutral position.
In the step-by-step shifting operation, the automatically shifted motor vehicle transmission is shifted manually by the driver. By swivelling the selector lever out of a center position, he can, in each case, shift up or down by one gear, depending on the direction into which he moves the selector lever. After each shifting operation, the selector lever moves back into its center position.
German Patent Document DE 39 29 268 A1 describes a selecting device with one operating plane in the longitudinal direction of the vehicle and one operating plane perpendicular thereto, in the case of which the selector lever automatically moves back from some operating directions into its starting position.
Since here only the control unit of the automatically shifted motor vehicle transmission is controlled by way of the selector lever, another operating element is required for controlling cruise control functions.
It is therefore an object of the invention to develop a selecting device for an automatically shifted motor vehicle transmission such that no operating element for controlling cruise control functions is required.
According to the invention, this object is achieved by providing a selecting device of the above-noted type wherein maximally four operating positions can be selected in each of the first and second operating modes by movement of the selector lever in two shifting channels which are essentially disposed perpendicularly with respect to one another, and wherein cruise control functions can be controlled by means of the selector lever in a third operating mode.
Further features and advantages of preferred embodiments of the invention are described in the specification and the claims.
According to the invention, in the case of a selecting device for selecting operating positions of an automatic transmission of a motor vehicle by the deflection of a selector lever, which automatically moves back from all deflecting directions for selecting the individual operating positions and by means of which the automatic transmission can be controlled in a first operating mode--selection of individual driving positions in the automatic operation--or in a second operating mode--step-by-step shifting of the gears in the manual operation--by means of a transmission control device, for each operating mode, one operating position respectively of the automatic transmission being assigned to each deflection direction of the selector lever, cruise control functions are controlled in that, by means of the selector lever, in two shifting channels, which are essentially disposed perpendicularly to one another, maximally four operating positions can be selected in each of the two operating modes and in that a third operating mode exists in which cruise control functions can be controlled by means of the selector lever.
Since an operating element for controlling cruise control functions is not required in preferred embodiments of the invention, advantages are obtained with respect to the assembly, the saving of costs and the weight.
In a preferred embodiment of the invention, it is provided that the selecting device has a change-over device, which is separate from the selector lever, for changing between the operating modes. This has the advantage that the individual operating modes can be selected in a simple manner.
If the selector lever is constructed as a steering column assembly lever, the driver's hand can advantageously remain at the steering wheel for operating the selecting device; likewise, if the selector lever is mounted directly on the steering wheel.
In another preferred embodiment of the invention, it is provided that a change-over device is constructed at the steering wheel, particularly by means of push buttons, which is separate from the selector lever. For operating the change-over device, the driver's hand can therefore also remain at the steering wheel.
In the case of an advantageous embodiment of the invention, it is provided that a movement of the selector lever directed essentially away from a driver in the first operating mode--stopped vehicle--causes the engaging of the driving position D of the automatic transmission, and in the case of a forward-driving vehicle, a holding of a constant speed, and in the second operating mode, a sequential upshifting of the automatic transmission, and in the third operating mode, acceleration during the drive.
In the case of another advantageous embodiment of the invention, it is provided that a movement of the selector lever directed essentially toward a driver in the first operating mode, when the vehicle is stopped, causes the engagement of the driving position R of the automatic transmission, and in the second operating mode, a sequential backshifting of the automatic transmission, and in the third operating mode, a reduction of the current speed to a stoppage.
Furthermore, it is advantageous according to certain preferred embodiments that a movement of the selector lever which is essentially directed transversely to a driver, toward the driver or upwards in the first operating mode causes an engagement of the driving position P of the automatic transmission and, in the third operating mode, a canceling of the current adjustments.
Likewise, it is advantageous according to certain preferred embodiments that a movement of the selector lever essentially transversely to a driver, away from the driver or downwards in the first operating mode causes an engagement of the driving position N of the automatic transmission and, in the third operating mode, a canceling of the current adjustments.
A combination of these selector lever functions advantageously causes on the whole an ergonomically favorable arrangement of all individual selectable operating positions of the automatically shifted transmission and of the cruise control functions.
In certain preferred embodiments of the invention, it is provided that a selecting device is constructed such that, at a driving speed of the motor vehicle below a certain rate, the transmission control device switches over automatically from the possibly selected third operating mode into the first operating mode. If the rate of the driving speed, below which an automatic change-over takes place, is, for example, at 20 km/h, this has the advantage that the driver, in speed ranges in which cruise control functions are rarely required, must not actively shift out of these.